W108 4.5: Engine Removal and Re-Installation.
 

What a great place this forum has been...learned a lot and inspired me to continue with my projects.

I recently found a clean 1972 280SE 4.5 with a seized engine that is in much better cosmetic condition than mine is, and purchased it. The plan is to take the engine out of the cosmetically-challenged car and put it into the better looking car. In a nutshell, every thing that I needed to address in my car, this car already had done....So I took the cars to a guy that seems to have extensive knowledge on these cars, and has worked on them when since they were new, and he recently started taking the cars apart.

My original car with the good engine obviously has some rust on the manifolds that needed a lot of working (read WD40) and looks like I might need some new manifold gaskets according to him, the bolts managed to come off but it seems welded together with rust.

The newer car has the seized engine, and since it will not turn, it is causing my mechanic untold headaches, especially when it comes to removing the torque converter...it appears the only other way to take it off involves working from the other end and jacking up (the newly rebuilt) transmission and that means more labour than originally intended (read $$$)...and that leaves me with a

Anybody with experiences with such situations to help us along our way will be greatly appreciated...will go and have a look at the car this Sunday and maybe scratching my head while looking into the engine bay might help...maybe not by much, but every little bit helps. The necessary gaskets and engine mounts and filters and most hoses have been bought to aid the project along but I will also take stock of what the situation is and replace as needed.

...meanwhile, all my other (non-MB) cars are deciding to act up, wish this project was done already!


Thanks, comrades.

better to remove the engine and transmission together and install the same way
regards
ad

Even easier to drop the whole front end with engine and trans as a unit.

If your old trans was rebuilt and you really want to save it it would be a lot easier to pop off the oil pan from the old engine and remove the connecting rods. My money is on a broken timing chain rail causing valve/piston interference on the old engine so removal of 4 conn rods from the bad side would allow engine rotation.

The seized engine has a newly rebuilt transmission done by previous owner. The good engine has a leaky transmission, which I've been topping off. The seized engine also has a new exhaust system also installed by previous owner, albeit an incorrect single pipe instead of twin pipe exhaust. Will go down and have a look today and see if its possible to drop the front end. I also suspect a broken timing chain as well, Tomguy, will look into that, should go down this afternoon and have a look.

I dont have any pics of the V8's i have done but I have a little jockey I bolt to the trans, undo the front flat springs,undo the body mount bushes each side ,undo the the steering box, the shock absorbers,cut the brakes hoses ( never use old ones) and disconnect the drag ling and steering damper from the idler.
Lift the front . Here i am installing a OM616 diesel into my W110 station wagon. A lot easier than lifting it in the top and it gives you the oppurtunity to repair and detail the front end. Tghese suspensions work very well if in good condition and once you have done it,you need never worry about it for another 40-50 years.

Thanks for the photo...my guy managed to get out my good engine and now he is working on getting out the seized engine from the other car. I suppose its a question of elbow grease when it comes to taking on such tasks and you have to be mentally ready to tackle it...

If the engine is seized by rust in the pistons you can pull the plugs and pour in some WD-40 or any other good rust buster. I use a brand called Sea-Foam but it is not available everywhere yet.

By the way, it is not the piston that will be rusted to the block but the piston rings. This is a small point, but the reality of this is that you might have to keep pouring the WD-40 in for a few days. You can also use automatic transmission fluid to bust rust if you have an old bottle of that laying around.

So how can you tell if it is rusted or busted? If it will just not move at all it is likely rust. If it will move a little and then hits a hard stop it is a mechanical problem.

You might also pull the pan and look for a broken rod bearing cap. Usually the bolts holding the cap break and allow the cap to move and when this takes place there is a HARD slam inside the block. FYI: If you find this to be the case then the crank is likely bent so if anyone plans on reusing it they should have it checked first by a shop that can do this.

We managed to get the a/c compressor and water pump et al out and managed to clear the torque convertor and extract the engine. In the process it appears that there are a few issues that would be wise to address while the engine is out.

1. Replace the fuel injector electrical connectors. One appears to have been fixed along with one of the injectors, the rest are brittle and require attention. Photo attatched.

2. Source a rebuilt A6 A/C compressor and replace along with pulley. Got no problems sourcing a pulley, but the pricing of the compressor.....yeah. Would love to get this taken care of now but the budget is already stretched to its max right now...

3.Replace exhaust/muffler o-rings (2 passenger and 1 driver's side).

4. Wiper washer fluid reservoir tube is corroded by battery acid.

I've already got replacement engine mounts, as well as the necessary gaskets and o-rings that accompany this job, hopefully we can get this baby done in good time. Will try and post pics.

Have you looked at installing a Sankyo or sanden air con compressor ?

Lot more efficient than the old heavy A6 units.

Will look into that...any idea what part number I would be looking at?

Where would I find a Sanden or Sankyo air compressor that would replace the current A6 GM compressor?

This is the best deal I have found:

A-6 to Sanden Conversion Kit - Compressors

This kit includes the Sanden compressor and the adapter bracket and hardware to mount it in place of the A6 compressor.

Tom

Thanks Tom, I should have been more creative with my searches...I'm having to go back and forth with the supplier on the A6 GM that I settled for....confusion with the metric vs american thread bolts (mine requires the american thread).

The harrison/gm compressors were all SAE thread units until the first W123 and W126 units arrived and then they supplied metric units to mercedes so you can get unstuck trying to fit a reco unit that may have started life on a W126 380 or something. They are heavy lump and you would be better off fitting a more modern lighter unit . in fact you can even buy alloy repro A6's which are 1/3 the weight of the boat anchor units of the past.